protected override async Task <bool> Read(bool addEmptyElement = true) { if (await base.Read(addEmptyElement)) { ProductSubcategoryList subcategories; try { subcategories = await ProductsServiceClient.GetProductSubcategoriesAsync(); } catch (Exception exception) { DisplayAlert(exception); return(false); } foreach (var subcategory in subcategories) { items.Add(subcategory); } } return(true); }